What does a slight superior meniscus root displacement mean? Does it mean a tear at the meniscus? Treament options if any?

Depends. Are you looking at MRI report? Superior means top and root is at the back attachment of the meniscus. The meniscus does have mobility and can move in relation to the position of the knee. If the meniscus is displaced from the capsule then yes, it could be a tear. Swelling, localized joint pain, locking or giving way are signs of possible meniscal problems. Treatment depends on how it effects you.